The subject matter described and/or illustrated herein relates generally to electrical connector systems and, more particularly, to electrical connectors that are mounted on circuit boards.
To meet digital multi-media demands, higher data throughput is often desired for current digital communications equipment. Electrical connectors that interconnect circuit boards must therefore handle ever increasing signal speeds at ever increasing signal densities. One application environment that uses such electrical connectors is in high speed, differential electrical connectors, such as those common in the telecommunications or computing environments. In a traditional approach, two circuit boards are interconnected with one another in a backplane and a daughter board configuration. However, at the footprints of the circuit boards where the electrical connectors connect thereto it may be difficult to improve density while maintaining electrical performance and/or reasonable manufacturing cost. For example, in known circuit boards, signal vias within the circuit boards are plated, creating plated through holes (PTHs) that are electrically connected to corresponding traces in the circuit board. Contacts extending from the electrical connectors are connected to the PTHs, and thus the traces, using eye-of-the-needle contacts. Similarly, ground vias are routed through the circuit boards, which are also plated, creating PTHs, which connect to ground contacts of the electrical connectors.
Positioning the ground PTHs around the signal PTHs has an effect of reducing cross-talk, however, the interactions between the ground and signal PTHs can still create electrical problems, such as by lowering impedance. One method of improving such footprints is to counterbore a portion(s) of the signal PTHs to remove the plating to an area just in the vicinity of the corresponding trace in the circuit board. However, the same problems still remains in the short length of the non-bored PTHs that remain for interfacing the contacts with the traces. This region, though short, still interacts with the neighboring ground PTHs to lower impedance, which becomes increasingly problematic at higher transmission speeds.
To achieve higher system densities and speed, further improvement of circuit board footprints and connections to the circuit boards must be made over known approaches. There is a need for an electrical connector that enables improvement of the density and/or electrical performance of circuit board footprints to achieve higher system densities and/or higher system speeds.